Flash-light composition.



UNITED. S A ES PEENT OFFICE; v

ARTHUR EIQHENGRUN, or ELBERFELD, GERM NnAssIGNoR-To FAR- f BENFABRIKENOFELBERFELD 00., OF NEW YORK, N. Y., A CORPO- RATION on NEW YORK.

FLASH-LIGHT COMPOSITION.-

Specification of Letters Patent.

Applicatio med June 17'. 1905. Serial No- 265,806.

To all whom it may cancer-m,

Be it known that I, ARTHUREICHENGBJIZ'IN, doctor of hilosophy, chemist,residing at Elberfeld, ermany, (assignor to the FARBEN- FABRIKEN OFELBERFELD Co., of New York,)

have invented a new and useful Improvement however, which re uire alonger timee. g.,

large s1zes of plates,

for exposures Wit whereby the lens must be stoppedrlown for indoorportraiture, enlargement &c. -flash light powders must beused thecombustion of which is slow. Such owders have hitherto been prepared byad ing indifierent substances, such as gypsum or the like, to theflash-lights in order to lengthen the burning. Of course by suchadmixtures the luminosity produced is considerably reduced;

I have now found that slowly-burning flashlight powders givinga lightof-great intensity, richin actinic power, which powders generate verylittle smoke and are proof "against accidental explosion, can beprepared by mixing tungsten'compounds glving ofi oxygen,

such as tungstic acid or 'tungstates with easily-combustible metallicpowders, which produce a light of great intensity, such as magnesium oraluminium, 8pc. Such a flashe; g., obtained by intimately mixing onepart tungstic acid .or its sodium or calcium salt.

Of course there may .be added to these powders other suitablesubstances, such as strontium nitrate, in order to obtain a coloredflame or it may be to shorten or lengthen the time of combustion or thelike.

Having now described my invention and in what manner the same is to beperformed, what I claim as new, and desire'to selfire by Letters Patent,is

1. lhe herem described new flash-light owders being prepared frommetallic powers, which have a strong afiinity for ox gen and aretherefore e ily combustible an the combustion of whi'c produces a li htof great intensity, with tungstic acid and erivatives,

which flash-light owders burn slowly in comparison to the or inaryflash-lights for instan- 2. The herein described new flash light powderbeing a mixture of magnesiumwith tungstates, substantially as described.

In testimony whereof I have signed. my name in thepresence of twosubscribing witnesses.

ARTHUR EIQHENGRI' JN,

Witnesses;

OTTO Kome, -J. A. RITTERSHAUS.

Patented Fees, 1906.

light burning off during several seconds is,-

